Golang NullInt64.Scan方法代碼示例

// Scan a value into the Int64, error on nil or unparsable
func (i *Int64) Scan(value interface{}) error {
	tmp := sql.NullInt64{}
	tmp.Scan(value)

	if tmp.Valid == false {
		// TODO: maybe nil should be simply allowed to be empty int64?
		return errors.New("Value should be a int64 and not nil")
	}
	i.Int64 = tmp.Int64

	i.DoInit(func() {
		i.shadow = tmp.Int64
	})

	return nil
}

func TestNullTypeInt64(t *testing.T) {
	var userID sql.NullInt64
	userID.Scan(nil)
	b := Eq{"user_id": userID}
	sql, args, err := b.ToSql()

	assert.NoError(t, err)
	assert.Empty(t, args)
	assert.Equal(t, "user_id IS NULL", sql)

	userID.Scan(int64(10))
	b = Eq{"user_id": userID}
	sql, args, err = b.ToSql()

	assert.NoError(t, err)
	assert.Equal(t, []interface{}{int64(10)}, args)
	assert.Equal(t, "user_id = ?", sql)
}

func (s *scanner) Scan(src interface{}) error {
	var err error

	switch s.value.Type().Kind() {
	case reflect.Struct:
		nt := mysql.NullTime{}
		err := nt.Scan(src)
		if err != nil {
			return err
		}
		s.value.Set(reflect.ValueOf(nt.Time))
	case reflect.Bool:
		nb := sql.NullBool{}
		err := nb.Scan(src)
		if err != nil {
			return err
		}
		s.value.SetBool(nb.Bool)
	case reflect.String:
		ns := sql.NullString{}
		err = ns.Scan(src)
		if err != nil {
			return err
		}
		s.value.SetString(ns.String)
	case reflect.Int64:
		ni := sql.NullInt64{}
		err = ni.Scan(src)
		if err != nil {
			return err
		}
		s.value.SetInt(ni.Int64)
	case reflect.Float64:
		ni := sql.NullFloat64{}
		err = ni.Scan(src)
		if err != nil {
			return err
		}
		s.value.SetFloat(ni.Float64)
	}
	return nil
}

func fetchResult(itemT reflect.Type, rows *sql.Rows, columns []string) (reflect.Value, error) {
	var item reflect.Value
	var err error

	switch itemT.Kind() {
	case reflect.Map:
		item = reflect.MakeMap(itemT)
	case reflect.Struct:
		item = reflect.New(itemT)
	default:
		return item, db.ErrExpectingMapOrStruct
	}

	expecting := len(columns)

	// Allocating results.
	values := make([]*sql.RawBytes, expecting)
	scanArgs := make([]interface{}, expecting)

	for i := range columns {
		scanArgs[i] = &values[i]
	}

	if err = rows.Scan(scanArgs...); err != nil {
		return item, err
	}

	// Range over row values.
	for i, value := range values {

		if value != nil {
			// Real column name
			column := columns[i]

			// Value as string.
			svalue := string(*value)

			var cv reflect.Value

			v, _ := to.Convert(svalue, reflect.String)
			cv = reflect.ValueOf(v)

			switch itemT.Kind() {
			// Destination is a map.
			case reflect.Map:
				if cv.Type() != itemT.Elem() {
					if itemT.Elem().Kind() == reflect.Interface {
						cv, _ = util.StringToType(svalue, cv.Type())
					} else {
						cv, _ = util.StringToType(svalue, itemT.Elem())
					}
				}
				if cv.IsValid() {
					item.SetMapIndex(reflect.ValueOf(column), cv)
				}
			// Destionation is a struct.
			case reflect.Struct:

				index := util.GetStructFieldIndex(itemT, column)

				if index == nil {
					continue
				} else {

					// Destination field.
					destf := item.Elem().FieldByIndex(index)

					if destf.IsValid() {

						if cv.Type() != destf.Type() {

							if destf.Type().Kind() != reflect.Interface {

								switch destf.Type() {
								case nullFloat64Type:
									nullFloat64 := sql.NullFloat64{}
									if svalue != `` {
										nullFloat64.Scan(svalue)
									}
									cv = reflect.ValueOf(nullFloat64)
								case nullInt64Type:
									nullInt64 := sql.NullInt64{}
									if svalue != `` {
										nullInt64.Scan(svalue)
									}
									cv = reflect.ValueOf(nullInt64)
								case nullBoolType:
									nullBool := sql.NullBool{}
									if svalue != `` {
										nullBool.Scan(svalue)
									}
									cv = reflect.ValueOf(nullBool)
								case nullStringType:
									nullString := sql.NullString{}
									nullString.Scan(svalue)
									cv = reflect.ValueOf(nullString)
								default:
									var decodingNull bool

									if svalue == "" {
//.........這裏部分代碼省略.........

// Scan implements the Scanner interface.
func (ns *Int) Scan(value interface{}) error {
	n := sql.NullInt64{Int64: int64(ns.Int)}
	err := n.Scan(value)
	ns.Int, ns.Valid = int(n.Int64), n.Valid
	return err
}

// Scan implements the Scanner interface.
func (ns *UInt32) Scan(value interface{}) error {
	n := sql.NullInt64{Int64: int64(ns.UInt32)}
	err := n.Scan(value)
	ns.UInt32, ns.Valid = uint32(n.Int64), n.Valid
	return err
}